List of top Chemistry Questions

The fusion of chromite ore with sodium carbonate in the presence of air leads to the formation of products A and B along with the evolution of CO$_2$. The sum of spin-only magnetic moment values of A and B is ______ B.M. (Nearest integer)
(Given atomic number: C : 6, Na : 11, O : 8, Fe : 26, Cr : 24)

Number of compounds from the following with zero dipole moment is _______.
HF, H$_2$, H$_2$S, CO$_2$, NH$_3$, BF$_3$, CH$_4$, CHCl$_3$, SiF$_4$, H$_2$O, BeF$_2$

The product Ⓒ in the following sequence of reactions has _______ π bonds.

The correct statements among the following, for a "chromatography" purification method is:

Match List-I with List-II.

List-I Alkali Metal	List-II Emission Wavelength in nm
(A) Li	(I) 589.2
(B) Na	(II) 455.5
(C) Rb	(III) 670.8
(D) Cs	(IV) 780.0

Choose the correct answer from the options given below:

X of enthanamine was subjected to reaction with \(NaNO_2/HCl\) followed by hydrolysis to liberate \(N_2\) and HCl. The HCl generated was completely neutralised by 0.2 moles of NaOH. X is ____ g.

In the Claisen-Schmidt reaction to prepare 351 g of dibenzalacetone using 87 g of acetone, the amount of benzaldehyde required is _________g. (Nearest integer)

Arrange the following elements in the increasing order of number of unpaired electrons in it.
(A) Sc
(B) Cr
(C) V
(D) Ti
(E) Mn
Choose the correct answer from the options given below:

The incorrect statements regarding enzymes are
(A) Enzymes are biocatalysts.
(B) Enzymes are non-specific and can catalyse different kinds of reactions.
(C) Most Enzymes are globular proteins.
(D) Enzyme - oxidase catalyses the hydrolysis of maltose into glucose.
Choose the correct answer from the option given below:

Consider the above chemical reaction. Product "A" is:

The major products formed:

A and B respectively are:

Identify the product A in the following reaction.

Consider the following single step reaction in gas phase at constant temperature.
\(2A_{(g)} + B_{(g)} → C_{(g)}\)
The initial rate of the reaction is recorded as $r_1$ when the reaction starts with 1.5 atm pressure of A and 0.7 atm pressure of B. After some time, the rate $r_2$ is recorded when the pressure of C becomes 0.5 atm. The ratio $r_1 : r_2$ is _______ $\times 10^1$. (Nearest integer)

In an atom, total number of electrons having quantum numbers n = 4, $|m_l|$ = 1 and $m_s$ = $-\frac{1}{2}$ is ________.

Given below are two statements: Statement I: $\text{PF}_5$ and $\text{BrF}_5$ both exhibit $\text{sp}^3\text{d}$ hybridisation.Statement II: Both $\text{SF}_6$ and $[\text{Co}(\text{NH}_3)_6]^{3+}$ exhibit $\text{sp}^3\text{d}^2$ hybridisation. In the light of the above statements,choose the correct answer from the options given below:

How can an electrochemical cell be converted into an electrolytic cell ?

During the detection of acidic radical present in a salt, a student gets a pale yellow precipitate soluble with difficulty in $\text{NH}_4\text{OH}$ solution when sodium carbonate extract was first acidified with dil. $\text{HNO}_3$ and then $\text{AgNO}_3$ solution was added. This indicates the presence of:

Evaluate the following statements related to group 14 elements for their correctness.
(A) Covalent radius decreases down the group from C to Pb in a regular manner.
(B) Electronegativity decreases from C to Pb down the group gradually.
(C) Maximum covalence of C is 4 whereas other elements can expand their covalence due to presence of d orbitals.
(D) Heavier elements do not form ppi-ppi bonds.
(E) Carbon can exhibit negative oxidation states.
Choose the correct answer from the options given below:

Combustion of 1 mole of benzene is expressed as C$_6$H$_6$(l) + $\frac{15}{2}$O$_2$(g) → 6CO$_2$(g) + 3H$_2$O(l). The standard enthalpy of combustion of 2 mol of benzene is x kJ. x = __________
(1) standard Enthalpy of formation of 1 mol of C$_6$H$_6$(l), for the reaction 6C(graphite) + 3H$_2$(g) → C$_6$H$_6$(l) is 48.5 kJ mol$^{-1}$.
(2) Standard Enthalpy of formation of 1 mol of \(CO_2\)(g),  for the reaction 6(graphite) + \(O_2(g)\) → CO$_2$(g) is -393.5 kJ mol$^{-1}$.
(3) Standard Enthalpy of formation of 1 mol of H$_2$O(l), for the reaction H$_2$(g) + $\frac{1}{2}$O$_2$(g) → H$_2$O(l) is -286 kJ mol$^{-1}$.

The incorrect statement regarding the geometrical isomers of 2-butene is:

Number of carbocation from the following that are not stabilized by hyperconjugation is _________ .

When '$x \times 10^{-2} \, \text{mL}$' methanol (molar mass $= 32 \, \text{g}$; density $= 0.792 \, \text{g/cm}^3$) is added to $100 \, \text{mL}$ water (density $= 1 \, \text{g/cm}^3$), the following diagram is obtained.

x = __________ (nearest integer)  
[Given: Molal freezing point depression constant of water at $273.15 \, \text{K}$ is $1.86 \, \text{K kg mol}^{-1}$]

Match List-I with the List-II

List-I (Hybridization)	List-II (Orientation in Space)
(A) sp3	(I) Trigonal bipyramidal
(B) dsp2	(II) Octahedral
(C) sp3d	(III) Tetrahedral
(D) sp3d2	(IV) Square planar

Choose the correct answer from the options given below:

In Reimer - Tiemann reaction, phenol is converted into salicylaldehyde through an intermediate. The structure of intermediate is ______.

The ratio $\frac{K_P}{K_C}$ for the reaction: